Shopify Core Web Vitals: The Order to Fix LCP, INP, and CLS

Google's good-score thresholds for shopify core web vitals are fixed: Largest Contentful Paint under 2.5 seconds, Interaction to Next Paint under 200 milliseconds, and Cumulative Layout Shift under 0.1, each measured at the 75th percentile of real visitor data. A store passes only when 75% of its visitors hit a good score on all three, at the URL level, in the same dataset. Fixing them out of order wastes developer hours chasing a metric that was never the bottleneck.

Why Shopify stores struggle here more than most

The average Shopify store scores between 25 and 30 out of 100 on speed, a range Shopify itself calls poor; it defines 50+ as acceptable and 60+ as fast. Third-party app scripts drive most of that gap, causing an estimated 60 to 80% of Shopify slowdowns. A typical store runs 15 to 25 apps, and stores hitting real performance trouble often run 30 or more. Each app can add 50 to 500 KB of JavaScript and CSS to every single page load, even pages where the app does nothing, and combined app scripts can add 1 to 3 MB of extra weight, several times heavier than the theme underneath them.

Fix LCP first

LCP goes first because it is the hardest of the three to pass. Per the 2025 Web Almanac, only 62% of mobile pages achieve a good LCP score, and it drives the visitor's first impression of speed before any interaction happens. On Shopify, the usual culprits are an unoptimized hero image, apps injecting content above the fold, and render-blocking scripts loading before the main image does.

• Compress and serve the hero or featured product image in a modern format, and preconnect to the domains serving it, without lazy-loading the actual LCP element itself.
• Move or remove any app script that injects banners, popups, or widgets above the fold before the main content has painted.

Fix INP second

INP replaced FID as the responsiveness metric and measures how fast the page reacts to a real click, tap, or keypress. Third-party scripts make up close to 62% of total JavaScript on the average store, and heavy scripts blocking the main thread are the usual cause of a poor score. Audit installed apps for ones running on every page instead of only where needed, defer or load non-critical scripts after the main content, and remove apps that duplicate functionality already built into the theme.

Fix CLS last

CLS is normally the cheapest and fastest of the three to fix, which is why it comes last rather than first: solving it early does not unlock the bigger LCP or INP wins waiting underneath it. Reserve fixed space for images, embeds, and ad slots before they load, and avoid injecting dynamic content, like a cookie banner or app widget, above content that already rendered. Once LCP and INP are under control, CLS fixes take a fraction of the time and close out the pass on all three metrics.

This fix order assumes you already know your store is slow. If you have not diagnosed why yet, why your Shopify store is slow to load covers the general audit. Once you know the cause, our Shopify development team can work through LCP, INP, and CLS in this order without re-testing from scratch after each change.